The one thing missing from Capital in the 21st Century, because it would have overshadowed everything else, is the massive transfer of wealth from the rentier class prior to WWII: both from the pogroms of Russia and then the Soviet Union, and the confiscation of wealth and property of Europe.
Basically the post-war boom was fueled by money stolen from the Jews.
Piketty does point out that Chicago-school monetarism is pretty much bullshit because its models are all based on that massive influx of wealth, which is one of his arguments for bailing on the US. But yeah - think on that for a moment. Saint Milton Friedman and his posse? Yeah, their economics work best when your initial conditions involve six million dead Jews.